Abstract: The objective of this study was to understand the mechanisms underlying changes in the color stability of high-oxygen modified atmosphere packaged (HiOx-MAP) steak during storage. The variations in meat color traits and sarcoplasmic proteome of longissimus dorsi steaks after different storage periods (0, 5, 10 and 15 days) were compared. The results suggested that the color stability of steaks decreased over time, which may be due to a significant decrease in metmyoglobin reducing activity (MRA) and oxygen consumption rate (OCR) during storage. The proteomic analysis revealed that a total of 20 differentially abundant proteins were identified during storage, 15 proteins of which were closely correlated with meat color traits and were identified as enzymes involved in glycolytic and energy metabolism (pyruvate kinase, glyceraldehyde-3-phosphate dehydrogenase, fructose-bisphosphate aldolase, fructose-1,6-bisphosphatase isozyme 2, malate dehydrogenase, and flavin reductase). The expression levels of these metabolic enzymes were downregulated to different extents with increasing storage time, thereby reducing NADH and NADPH levels and consequently meat color stability. Moreover, the decrease in meat color stability also may be related to the down-regulation of myoglobin expression during storage. Oxidative environments could induce the expression of peroxiredoxin-2, heat shock protein and protein DJ-1 to resist oxidative stress, and these proteins were closely correlated with meat color parameters. These findings indicate that the influence of high-oxygen modified atmosphere packaging on meat proteome will directly determine changes in meat color stability throughout storage.

Key words: meat color, high-oxygen modified atmosphere packaging, storage process, proteome